1. Field of the Invention
This invention relates to a two-stage network system with two-stage connected switching hubs.
2. Description of the Related Art
Conventionally, a network system with multistage connected switches such as FAT Tree has been known. JP-A-2010-288168 discloses an example of the conventional network systems with multistage connected switches. For example, a two-stage network system includes a plurality of lower layer leaf switches (lower switches), and a plurality of upper layer root switches (upper switches). Each lower switch is connected to all the upper switches. Also, the lower switches are connected to a desired number of terminals. Transmission and reception of frames between the different lower switches is made via any one of the plural upper switches.